From ca1c82642a72d32241691d3cb4fc91691eae57d8 Mon Sep 17 00:00:00 2001
From: Norman Maurer <nmaurer@redhat.com>
Date: Wed, 18 Dec 2013 13:55:15 +0100
Subject: [PATCH] Limit the access of the HttpHeaders for performance reasons

---
 .../handler/codec/http/HttpObjectDecoder.java | 22 ++++++++++++-------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/codec-http/src/main/java/io/netty/handler/codec/http/HttpObjectDecoder.java b/codec-http/src/main/java/io/netty/handler/codec/http/HttpObjectDecoder.java
index 88585cd965..5e1c07076a 100644
--- a/codec-http/src/main/java/io/netty/handler/codec/http/HttpObjectDecoder.java
+++ b/codec-http/src/main/java/io/netty/handler/codec/http/HttpObjectDecoder.java
@@ -110,6 +110,7 @@ public abstract class HttpObjectDecoder extends ReplayingDecoder<HttpObjectDecod
     private HttpMessage message;
     private long chunkSize;
     private int headerSize;
+    private long contentLength = Long.MIN_VALUE;
     private final AppendableCharSequence sb = new AppendableCharSequence(128);
 
     /**
@@ -222,7 +223,7 @@ public abstract class HttpObjectDecoder extends ReplayingDecoder<HttpObjectDecod
                 reset();
                 return;
             }
-            long contentLength = HttpHeaders.getContentLength(message, -1);
+            long contentLength = contentLength();
             if (contentLength == 0 || contentLength == -1 && isDecodingRequest()) {
                 out.add(message);
                 out.add(LastHttpContent.EMPTY_LAST_CONTENT);
@@ -236,7 +237,7 @@ public abstract class HttpObjectDecoder extends ReplayingDecoder<HttpObjectDecod
 
             if (nextState == State.READ_FIXED_LENGTH_CONTENT) {
                 // chunkSize will be decreased as the READ_FIXED_LENGTH_CONTENT state reads data chunk by chunk.
-                chunkSize = HttpHeaders.getContentLength(message, -1);
+                chunkSize = contentLength;
             }
 
             // We return here, this forces decode to be called again where we will decode the content
@@ -371,8 +372,6 @@ public abstract class HttpObjectDecoder extends ReplayingDecoder<HttpObjectDecod
 
         // Handle the last unfinished message.
         if (message != null) {
-            HttpMessage message = this.message;
-            this.message = null;
 
             // Check if the closure of the connection signifies the end of the content.
             boolean prematureClosure;
@@ -383,9 +382,9 @@ public abstract class HttpObjectDecoder extends ReplayingDecoder<HttpObjectDecod
                 // Compare the length of the received content and the 'Content-Length' header.
                 // If the 'Content-Length' header is absent, the length of the content is determined by the end of the
                 // connection, so it is perfectly fine.
-                long expectedContentLength = HttpHeaders.getContentLength(message, -1);
-                prematureClosure = expectedContentLength > 0;
+                prematureClosure = contentLength() > 0;
             }
+            reset();
 
             if (!prematureClosure) {
                 out.add(LastHttpContent.EMPTY_LAST_CONTENT);
@@ -419,7 +418,7 @@ public abstract class HttpObjectDecoder extends ReplayingDecoder<HttpObjectDecod
     private void reset() {
         HttpMessage message = this.message;
         this.message = null;
-
+        contentLength = Long.MIN_VALUE;
         if (!isDecodingRequest()) {
             HttpResponse res = (HttpResponse) message;
             if (res != null && res.getStatus().code() == 101) {
@@ -499,7 +498,7 @@ public abstract class HttpObjectDecoder extends ReplayingDecoder<HttpObjectDecod
             nextState = State.SKIP_CONTROL_CHARS;
         } else if (HttpHeaders.isTransferEncodingChunked(message)) {
             nextState = State.READ_CHUNK_SIZE;
-        } else if (HttpHeaders.getContentLength(message, -1) >= 0) {
+        } else if (contentLength() >= 0) {
             nextState = State.READ_FIXED_LENGTH_CONTENT;
         } else {
             nextState = State.READ_VARIABLE_LENGTH_CONTENT;
@@ -507,6 +506,13 @@ public abstract class HttpObjectDecoder extends ReplayingDecoder<HttpObjectDecod
         return nextState;
     }
 
+    private long contentLength() {
+        if (contentLength == Long.MIN_VALUE) {
+            contentLength = HttpHeaders.getContentLength(message, -1);
+        }
+        return contentLength;
+    }
+
     private LastHttpContent readTrailingHeaders(ByteBuf buffer) {
         headerSize = 0;
         AppendableCharSequence line = readHeader(buffer);